Curcumin alleviated lipopolysaccharide-induced lung injury via regulating the Nrf2-ARE and NF-κB signaling pathways in ducks.

BACKGROUND: Under the intensive modern poultry farming system, the lung of duck is one of the main target organs for various bacterial and viral infections. Curcumin is a kind of natural polyphenol compound for which various beneficial biological functions exist, including being an anti-inflammatory, antioxidant, and antiviral. The aim of this work was to investigate the mechanism of curcumin-alleviated lipopolysaccharide (LPS)-induced lung damage by the nuclear erythroid 2-related factor 2 (Nrf2)-antioxidant reaction element (ARE) and nuclear factor kappa B (NF-κB) signaling pathway in ducks. RESULTS: In total, 450 one-day-old male specific pathogen-free ducks were randomly assigned into three dietary treatments: CON, basal diet; LPS, basal diet + LPS treatment; LPS + CUR, basal diet + LPS + 500 mg kg-1 of curcumin. At the end of the experiment (21 days), ducks in LPS treatment were challenged with 5 mg LPS per kilogram of body weight and the other two treatments were injected with the same dose of phosphate-buffered saline solution. The results showed that LPS caused acute inflammation, oxidation stress, and lung injury. Dietary addition of curcumin significantly relieved the oxidation stress and inflammation parameters. Moreover, the results showed that remission may be through the signaling pathways of both Nrf2-ARE and NF-κB. CONCLUSION: In conclusion, dietary supplementation of 500 mg kg-1 of curcumin exhibited a lung-protective effect in ducks. This experiment broadens the mode of metabolism actions of curcumin in the target organs and provides an insight for the application of curcumin in waterfowl feed. © 2022 Society of Chemical Industry.

Design and high-level expression of a hybrid antimicrobial peptide LF15-CA8 in Escherichia coli.

Antimicrobial peptides (AMPs) have been paid considerable attention owing to their broad-spectrum antimicrobial activity and have great potential as novel antimicrobials. In this study, a novel hybrid peptide LF15-CA8 was designed on the basis of bovine lactoferricin (LfcinB) and cecropin A. The gene segment encoding LF15-CA8 was synthesized and cloned into pGEX-4T-BH to form pGEX-4T-LC1 containing one copy of the LF15-CA8 coding region. A series of recombinant vectors containing up to six multiple-copy LF15-CA8 coding regions, i.e., pGEX-4T-LCn (n = 1-6), were subsequently constructed, and used for transformation in Escherichia coli BL21(DE3). After induction with IPTG, pGEX-4T-LC1 and pGEX-4T-LC2 transformants successfully expressed fusion proteins GST-LF15-CA8 and GST-(LF15-CA8)2 in the form of inclusion bodies, respectively. The inclusion bodies were dissolved and the peptide was successfully released in 70 % formic acid in a single step. After purification, about 10.0 mg of the recombinant peptide LF15-CA8 with purity more than 97 % was obtained from 1 l of bacteria culture of pGEX-4T-LC2 transformants. LF15-CA8 caused an increase in antibacterial activity against Gram-positive bacterium (Staphylococcus aureus ATCC 25923) compared with the parent peptides and did not show obvious hemolytic activity against human erythrocytes in the range of effective antibacterial concentration. These results suggest that the peptide LF15-CA8 could be a promising candidate for therapeutic applications, and may lead to a cost-effective solution for the large-scale production of AMPs.

Prognostic risk stratification value of MACC1 expression in patients with gastric cancer.

BACKGROUND: The prognostic significance of metastasis-associated in colon cancer-1 (MACC1) has been explored in a variety of malignancies. However, its clinical relevance in patients with gastric cancer (GC) is limited, also remains controversial. METHOD: In this study, we retrospectively evaluated the prognostic value of lesion MACC1 expression in 347 GC patients. Lesion MACC1 expression was analyzed with immunohistochemistry and grouped as MACC1low (n = 172) and MACC1high (n = 175) cases. RESULTS: Data revealed that the degree of MACC1 expression is not related to patient sex, age and disease stage (all p > 0.05). Survival analysis showed that only post-operation advanced pT (p = 0.018), pN (p < 0.001), pM (p = 0.001) and AJCC stages (p < 0.001) are significantly associated with shorter survival, while no obvious difference was observed between MACC1low and MACC1high cases (p = 0.158). However, we found that survival for female (p = 0.032), older (p = 0.028), and early disease stage (pT stage I + II, p = 0.033) patients with MACC1high are remarkably worse than those with MACC1low. CONCLUSION: In summary, our findings revealed that, though MACC1 expression is not associated with the survival of the whole cohort, the prognostic risk stratification value of lesion MACC1 expression in subgroups of patients with gastric cancer should be noted.

Cell selectivity and interaction with model membranes of Val/Arg-rich peptides.

Antimicrobial peptides are major components of the innate self-defence system and a large number of peptides have been designed to study the mechanism of action. In the present study, a small combinatorial library was designed to study whether the biological activity of Val/Arg-rich peptides is associated with targeted cell membranes. The peptides were produced by segregating hydrophilic residues on the polar side and hydrophobic residues on the opposite side. The peptides displayed strong antimicrobial activity against Gram-negative and Gram-positive bacteria, but weak haemolysis even at a concentration of 256 µM. CD spectra showed that the peptides formed α-helical-rich structure in the presence of negatively charged membranes. The tryptophan fluorescence and quenching experiments indicated that the peptides bound preferentially to negatively charged phospholipids over zwitterionic phospholipids, which corresponds well with the biological activity data. In the in vivo experiment, the peptide G6 decreased the bacterial counts in the mouse peritoneum and increased survival after 7 days. Overall, a high binding affinity with negatively charged phospholipids correlated closely with the cell selectivity of the peptides and some peptides in this study may be likely candidates for the development of antibacterial agents.

Prevalence of human papillomavirus genotypes and relative risk of cervical cancer in China: a systematic review and meta-analysis.

High-risk HPV (hrHPV) is related to cervical carcinogenesis, although clinical data comparing the natural history and carcinogenic potential of type-specific HPV remain limited. Furthermore, the nationwide prevalence rates of overall and type-specific HPV among women with cervical precancerous lesions and cancer have not been reported. Here, a meta-analysis was performed for type-specific HPV distribution among 30,165 HPV-positive women, including 12,094 invasive cervical cancers (ICCs), 10,026 cervical intraepithelial neoplasia grade 2/3 (CIN2/3), 3246 CIN1, and 4799 normal cervices from 45 PCR-based studies. We found that HPV16 was the most common hrHPV type involved in cervical disease. The HPV16 positivity rate varied little across normal (22.7%) and CIN1 individuals (23.6%) but increased through the CIN2 (37.6%) and CIN3 patients (51.9%) to 65.6% in ICC cases. HPV16, 18, 35, 39, 45, and 59 were more frequent in ICC than CIN3, with ICC:CIN3 ratios ranging from 2.3 for HPV18 to 1.1 for HPV35/45. HPV31, 33, 52, and 58 were more frequent in CIN3 compared with normal cervices but less common in ICC compared with CIN3 (ICC:CIN3 ratios ranging from 0.6 for HPV58 and 0.4 for HPV52). The ICC:normal ratios were particularly high for HPV18, 52 and 58 in West China (4.1, 3.9 and 2.9, respectively) and for HPV45 and 59 in North China (1.6 and 1.1, respectively). In summary, this study is the most comprehensive analysis of type-specific HPV distribution in cervical carcinogenesis and could be valuable for HPV-based cervical cancer screening strategies and vaccination policies in China.

Recombinant expression and biological characterization of the antimicrobial peptide fowlicidin-2 in Pichia pastoris.

Fowlicidins are a group of cathelicidin antimicrobial peptides that were initially identified in chickens. Fowlicidin-2, which is composed of 31 amino acids, is widely expressed in the majority of tissues in chickens and has an important role in innate immunity. In the present study, a recombinant expression system for fowlicidin-2 was successfully constructed using Pichia pastoris X-33 and the expression vector pPICZα-A. Under the optimized fermentation conditions, 85.6 mg fowlicidin-2 with >95% purity was obtained from 1 liter culture medium following purification by ion exchange chromatography and reversed phase high performance liquid chromatography. The recombinant fowlicidin-2 exhibited broad spectrum antimicrobial activity and had a minimum inhibitory concentration ranging from 1 to 4 µM. Furthermore, recombinant fowlicidin-2 exhibited hemolytic activity, promoting 50% human erythrocyte hemolysis in the concentration range of 128-256 µM, and anticancer activity, resulting in the death of 50% of A375 human malignant melanoma cells in the concentration range of 2-4 µM. The results of the present study suggest that recombinant fowlicidin-2 may be a promising candidate for therapeutic applications.

Multimerization and fusion expression of bovine lactoferricin derivative LfcinB15-W4,10 in Escherichia coli.

Antimicrobial peptides are promising candidates for therapeutic and industrial application owing to their broad spectrum. In this work, a cost-effective method for expression of a potent antimicrobial peptide, bovine lactoferricin derivative LfcinB15-W4,10, has been developed. The oligonucleotide encoding the peptide was linked to generate different oligomeric oligonucleotide segments containing from one to nine but eight tandem copies which was inserted individually to the E. coli expression vector pET32a. The thioredoxin fusion peptides were successfully expressed and detected with different molecular weight on SDS gel, respectively. Among the monomer and other multimeric peptides, the tetramer was expressed at the highest level. After purification, more than 10 mg of tetramer with 99% purity was obtained from 1 l culture and exhibited similar antimicrobial activity as synthetic LfcinB15-W4,10 monomer. The expression system in this study provides a potential production method for lactoferricin derivatives and other antimicrobial peptides in research and industrial applications.

Fusion expression of bovine lactoferricin in Escherichia coli.

The drug resistance problem has been growing with the utilization of current antibiotics in feed and medical industries. LfcinB, a 25-amino acid antibacterial peptide derived from bovine lactoferrin, is one of potential alternatives of antibiotics. According to the bias of codon utilization of Escherichia coli, a fragment encoding LfcinB has been chemically synthesized, inserted into vector pGEX-4T-2 and expressed in E. coli. The antibacterial peptide was fused with GST with a protease cleavage site located between them. Two constructs with different cleavage sites were made. One construct, pGEX-Th-LfcinB, contains a thrombin cleavage site carried by the vector, and the other, pGEX-Th-Xa-LfcinB, contains a Factor Xa cleavage site which was introduced after the thrombin cleavage site. Fusion protein GST-Th-LfcinB protein was efficiently cleaved by thrombin, yielding recombinant LfcinB showing antibacterial activity. However, fusion protein GEX-Th-Xa-Lfcin B containing Factor Xa recognition site could not be cleaved by Factor Xa at the conditions tried in this study. Successful expression of LfcinB in E. coli provides a possible method to produce LfcinB in large amounts.